The present invention relates to an improved gate for a carabiner, and in particular, to a carabiner gate formed from sheet metal, such as may be used in rock climbing and rappelling.
The use of carabiners by rock climbers and rappellers has become widespread. As is shown in FIG. 1A, a carabiner, generally indicated at 10, is typically formed of a metallic body 14 which is formed into a generally prolate loop so as to circumscribe an opening or void 18. The carabiner 10 has a back portion 22, and a front portion, generally indicated at 26, which is either generally straight, as shown in FIG. 1A, or is concave.
The front portion 26 of the carabiner 10 is formed by an upper, free end 30 which extends downwardly from a top portion 34 of the carabiner body 14 in a hook-like manner, and a lower free end 38 which extends upwardly from a bottom portion 42 of the body. The space between the upper free end 30 and the lower free end 38 provides an opening, generally indicated at 46, through which climbing/rappelling ropes may be passed into the void 18 circumscribed by the body.
The opening 46 is selectively closed by a gate 50 which is pivotably attached to the lower free end 38. Typically, the gate is biased in a closed position, represented by the dashed lines 50a. In such a position, the gate prevents a rope which is held within the carabiner 10 from being pulled out through the opening 46. The gate also usually provides structural support to the body in tension. When it is desired to position another rope 56 within the carabiner 10, the rope is placed against the gate 50 and sufficient force is applied to overcome the biasing. This moves the gate into the position shown at 50, or even into the position shown at 50b. Those familiar with carabiners will appreciate that the rear portion 22 often provides a limitation to the distance which the gate 50 can be displaced.
Once the rope 56 is positioned within the void 18 circumscribed by the carabiner 10, the pressure on the gate 50 is released and it returns to the position shown at 50a. The rope 56 is thus properly held within the carabiner 10.
As shown in FIG. 1A, the gate 50 is generally cylindrical. Such a gate 50 has the advantage that it is easy to use, and the rounded outer surface 60 provides little friction against the rope 56. Those familiar with rock climbing and rappelling will be familiar with the high cost of ropes and the importance of minimizing wear. Unlike most other applications, a climber or rappeller must not use worn ropes, as one broken rope can result in severe injury or even death.
One problem with the gate 50 shown in FIG. 1A is that they are generally expensive to produce. Typically the gates are machined out of bar stock or extrusion metal. Machining the metal is generally more expensive and time consuming that other approaches such as stamping. Once the gate 50 has been machined, a spring (not shown) or some other biasing device must be loaded prior to attachment to the body 14 of the carabiner 10.
To overcome the problems and expense of machined gates, an alternative arrangement was developed in which the machined gate 50 is replaced by a piece of curved wire-like piece of metal. Referring now to FIG. 1B, there is shown a carabiner 110 with a body 114 circumscribing a void 118. The body 114 has a back side 122 and a generally straight front side 126. The body 114 also has a top portion 134 and a bottom portion 142 which support an upper free end 130 and a lower free end 138, respectively to form an opening 146.
Instead of having a machined gate, such as that shown in FIG. 1A, the opening 146 is selectively closed by a wire which is attached at each end to the lower free end 138. The wire forming the gate 150 is attached to the lower free end 138 in such a manner as to have a biased position, shown at 150a, in which a top 154 of the gate 150 rests in a notch 160 formed in the upper free end 130. In such a position, a rope (not shown) cannot be pulled through the opening 146.
The wire gate 150 has several advantages over the machined gate discussed above. First, it is easier to make and is less expensive. Second, it does not require a spring or other resilient member to be added. Rather, the biasing force is created by tension within the piece of metal. Third, the piece of metal provides the carabiner with less weight.
The wire gate 150 does have disadvantages. First, the wire causes increased wear on climbing and rappelling ropes. Instead of passing over one cylindrical body, the rope passes over two wires having a smaller curvature, causing greater wear. Additional concern is that some less experienced climbers may view the carabiners as being less safe due to the thinness of the wire compared to the conventional gate.
Thus, there is a need to provide a carabiner gate which overcomes the respective disadvantages of each type of currently available carabiner. Such a gate must be economical, durable and easy to use.